FIELD OF THE INVENTION
[0001] The present invention relates to a safe driving assist system of road vehicles by
providing drivers information through cooperation between a roadside system and an
in-vehicle system.
BACKGROUND OF THE INVENTION
[0002] Theconcepts, designingprocedures and the like of security devices for defending humans
from harm when a machine fails or humans make a mistake are described, for instance,
in JIS B 9705-1: SAFETY OF MACHINES, Safety-Related Portions of Control System Part
I: General Rules for Designing. In large-scale systems such as general industrial
machines or nuclear facilities, security is provided, based on the recognition that
humans make mistakes, to minimize intervention by humans. If intervention by humans
is required by any means, expert persons, who have been fully trained, are allowed
to operate the machines for security.
[0003] In contrast, in the automotive traffic system, although there is the licensing system,
the safety is generally secured based on observance of traffic rules and much attention
of non-professional drivers. The method of securing the automotive traffic system
generally has been traffic controls and educations of drivers.
[0004] Recently, to reduce careless mistakes of drivers, a sensor system is loaded on a
vehicle and alerts the driver at detecting obstacles around the vehicle. It is becoming
more and more popular, and further the safe driving support system has been developed
which detects dangerous situations at places where traffic accidents frequently occur
with sensors installed on the roadside and provides the driver information concerning
the dangerous situations.
[0005] The present invention relates to a safe driving support system which delivers information
concerning on the dangerous situations from the system installed on a roadside to
vehicles and drivers. With this system, if erroneous information indicating that there
is no danger is delivered from the roadside system to a vehicle and a driver when
there is a danger, and when the driver believes that the information is correct, the
driver falls in a dangerous situation, which is problemsome. This invention was made
for preventing occurrence of the problems as described above.
SUMMARY OF THE INVENTION
[0006] The present invention was made in the light of the circumstances as described above,
and it is an object of the present invention to provide a system security method which
is effective for security of the vehicle safe driving support system..
[0007] To achieve the object mentioned above, the system security method according to the
present invention is characterized in that, in the system of safe driving assist by
delivering information from a roadside system to vehicles and drivers thereof, when
a dangerous situation is not detected by a sensor when there is a danger on the road,
or when the system work is limited, or when a part of the system fails to work, information
on the impossibility of delivering accurate information concerning the road situation
is delivered to the vehicles and drivers to make the drivers careful and safe driving.
[0008] The system security method according to this invention has the configuration as described
above, so that it can effectively insure security of the safe driving support system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009]
Fig. 1 is a system block diagram illustrating one embodiment of the present invention;
Fig. 2 is a view illustrating the state where the system has been installed;
Fig. 3 is a table for safety analysis in each state of the system; and
Fig. 4 is a view illustrating an experiment with a driving simulator.
DETAILED DESCRIPTION OF THE INVENTION
[0010] One embodiment of the present invention is described in detail below with reference
to the drawings.
[0011] The safe driving support system comprises, as shown in Fig. 1, a roadside system
in turn comprising an obstacle detection sensor 2, a roadside equipment 3, a road-to-vehicle
communication equipment 4, a roadside message board 6 and a system on a vehicle 5.
This system is installed at a site hardly visible from drivers such as a curve road
as shown in Fig. 2 where traffic accidents frequently occur.
[0012] This system operates as described below. At first, the obstacle detection sensor
2 detects an obstacle 1 on the road, and delivers the information concerning a position
or a size of the obstacle to the roadside equipment 3. The roadside equipment 3 delivers
based on the information from the sensor, the information indicating that there is
an obstacle on the road to the roadside message board 6, and further delivers the
information via the road-to-vehicle communication equipment 4 to the vehicle 5. The
vehicle system 5 presents the received information to the driver according to the
running conditions of the vehicle or an operating state of the driver, and at the
appropriate timing. Thus the driver can know the situation before the vehicle arrives
at the site where the obstacle exists, and can evade the obstacle in good time.
[0013] If the obstacle detection sensor 2 does not detect the obstacle 1 when the obstacle
1 is on the road, the obstacles detection sensor 2 sends the information of "No obstacle"
to the roadside equipment 3. If the roadside equipment 3 shows a message of "No obstacle"
or no message on the roadside message board 6, drivers might recognize that there
is no obstacle on the road and might make a little attention to the road traffic condition.
Also when the information of "No obstacle" is sent via the road-to-vehicle equipment
4 and the vehicle gives the information of "No obstacle" or gives no information to
the driver, the driver might also make a little attention to the road traffic condition
based on the recognition that there is no obstacle on the road.
[0014] A table showing a result of analysis of the cases in which the safe driving support
system may cause the troubles in the dangerous state as described above in various
operating situations is shown in Fig. 3. In Fig. 3, the troubles in the dangerous
state is indicated by X. The section with the sign d indicates the trouble that the
sensor 2 can not detect the events in the dangerous state. The section with the sign
j indicates the trouble that the machine does not work properly and the state is not
recognized by drivers. The section with the sign n indicates the trouble that radio
wave transmitted from the road-to-vehicle communication equipment 4 do not arrive
vehicles because of blockage or interference due to multiple reflection. The section
with the sign p indicates the trouble that the device on the vehicle 5 does not operate
properly and no information is given to the driver. The section with the sign r indicates
the trouble that the driver does not recognize or ignores the information. Reducing
the troubles as shown in the table is important, but it is practically and theoretically
impossible to eliminate the troubles.
[0015] An object of the present invention is to provide the method of securing the system
safety even though any of the troubles as described above occurs. As described above,
security of the road traffic system is kept by drivers' attention. This invention
is concerning to alerting drivers for securing safety of the road traffic system.
[0016] In each of the states shown in Fig. 3, the sign a indicates the situation where erroneous
information is given, but the information is in the safe state. The signs b and c
indicate correct information. The signs e to h, k, and 1 indicate the state that the
given information may be correct and may not accurately reflect the road situations.
In these states, information advising the drives for safe driving is given to the
drivers. The signs i, j, m, and n indicate the situation where no information is given
and the vehicles can not provide proper services. For these cases no massage is given.
With the three types of state massages, a driver determines that, at least same message
must be given if the system works properly and any message is not given because the
system not working properly. In this case the driver carefully drives the vehicle.
The signs o and p indicate the state that the device on the vehicle 5 does not operate
properly, and the driver can carefully drive the vehicle like in the case when no
message is given. Education of drivers would be useful for the situations indicated
by the signs q and r.
[0017] The information required to advise drivers for safe driving may be considered to
be a message reflecting features of a site where the system is installed. In the experiment
with a driving simulator, the information of "Curve road ahead" as shown in Fig. 4
was given as notice information for safe driving. Regarding to the result of this
experiment, providing information is better than no message for driver's safety even
if a dangerous situation exists. By improving the way of presenting the information,
the system safety would be kept more than in the case of no message.
1. A security method of safe driving assist systean for road vehicles by providing information
from a roadside system to vehicles and drivers, wherein, for instance, when a sensor
does not detect the dangerous situation when a dangerous situation exists on a road,
when the work of the system is limited, or when a part of the system does not work,
the notice information indicating that the system can not work accurately is provided
to vehicles and drivers for safe driving.
2. The system security method according to claim 1, wherein the three types of information
enabling drivers to understand the road situations: namely at least information of
existence of a dangerous situation, notice information for drivers to make safe driving
because of possibility of a dangerous situation, and information indicating that the
system can not provide information are presented on a rode side message board and/or
an information display unit in each vehicle.
3. The system security method according to claim 1, wherein said the roadside system
provides the information indicating specific dangers to the site where the roadside
system is installed via a roadside message board and/or an information display unit
in each vehicle.